Information communication technology has been improved to the extent that it is possible for digital terminals to process text messages, voices and images with very high speed to service multimedia contents with two-dimensional images and voices. Information communication technology is further expected to be developed to a three-dimensional stereoscopic information communication service which is capable of providing multimedia services with stereoscopic and real impact.
Generally, stereoscopic images with three dimensional effects are possible based on the theory of stereo-eyesight by both eyes. An important factor for a three dimensional effect is the difference in optical angles of a person's two eyes, due to a distance of 65 mm therebetween, i.e., a parallax of the eyes. That is, each of the eyes respectively sees two different two-dimensional images, and when said two images are transferred via retina to the brain, the brain combines said transferred two images and reproduces the original three-dimensional image with sense of depth and sense of reality. This is generally referred to stereography.
A stereoscopic image display apparatus is classified into two generic types based on whether a user should wear a specific pair of glasses or not: a glasses-type of stereoscopic image display apparatus (stereoscopic image display apparatus) and a non-glasses-type of stereoscopic image display apparatus (auto-stereoscopic image display apparatus).
The stereoscopic image display apparatus gives a watcher inconvenience of wearing special glasses, while the auto-stereoscopic image display apparatus allows a watcher to enjoy three-dimensional images only by directly watching the screen even without wearing said glasses, and thereby the auto-stereoscopic image display apparatus solves problems with the stereoscopic image display apparatus. Therefore, there are many studies on the auto-stereoscopic image display apparatus going on nowadays. The auto-stereoscopic image display apparatus again can be classified into two generic types: apparatus by the lenticular method and apparatus by the parallax-barrier method.
As shown in FIG. 1 and FIG. 2, operation of the stereoscopic image display apparatus by the conventional parallax-barrier method are explained as follows. The stereoscopic image display apparatus by the conventional parallax-barrier method comprises a display module (10), wherein the left image (L) and the right image (R) respectively corresponding to the left eye and the right eye face towards the vertical direction (Y-Y′ direction in FIG. 2) and are disposed alternately in the horizontal direction (X-X′ direction in FIG. 2); and a blocking film in the form of a bar which is called a barrier (20), disposed at the front end and facing towards the vertical direction. This kind of stereoscopic image display apparatus has a system wherein said display module (10) and barrier (20) are disposed so as that the light for the left image (L) goes only into the left eye, and the light for the right image (R) goes only into the right eye, and thereby the divided two left and right images (L, R) are separately observed to give the stereoscopic sense.